A method for generating a three-dimensional image using parallax images, which includes of an image for a left eye (hereafter “left eye image”) and an image for a right eye (hereafter “right eye image”), which have parallax from each other, is known. Japanese Patent Application Laid-Open Nos. H5-7373, H9-116932, 2002-125246 and 2007-129436 disclose technologies related to parallax images.
As one parallax image generation method, a method for independently capturing a left eye image and a right eye image of a same object using two systems of image capturing units having parallax, such as two digital still cameras or double lenses of a digital still camera, which are set for generating parallax, has been proposed. Another method that has been proposed is generating a parallax image using image processing from an image captured by a single lens digital still camera. According to this method, a left eye image is captured by a single lens image capturing unit first, then the object image extracted from the left eye image is shifted by the amount of parallax, thereby a right eye image is generated.
A method for using a single lens image capturing unit may be implemented using a simple and compact configuration, but the following procedures are required. For example, in order to determine parallax for each of a plurality of objects when capturing the plurality of objects of which distances from the image pickup unit are different, the distance information of each object is required. Therefore instead of disposing a distance measuring unit, a plurality of images are captured while changing the focused object distance. Then by extracting the focused object image data from each captured image data, the extracted object image data and the focused object distance upon capturing the image are corresponded. Then by shifting the extracted object image data by the amounts of parallax according to the respective focused object distances and synthesizing this data, the right eye image data is generated.
If such a method is used, some degree of image capturing procedures is inevitably required. Hence an efficient image capturing operation is demanded in order to prevent a drop in throughput. Also when the extracted object image data is shifted and synthesized, image processing, which reproduces natural brightness and a perspective of an object, is demanded.